Absorbent pad dressing frame delivery system

ABSTRACT

A wound dressing and delivery system comprising carrier frame that overlaps a heavy absorbent pad on a thin backing of the wound dressing (with the backing sandwiched between the pad and carrier frame) so that the carrier frame and absorbent pad support (e.g., rigidify) the backing to facilitate handling. The carrier frame also has a window over the absorbent pad. Adhesive is provided one major surface of the backing, and the absorbent pad is provided on this major surface. The carrier frame is provided on the opposite major surface to the absorbent pad. The backing is preferably a very thin transparent or translucent elastic polymeric film, and the absorbent pad is relative thick, heavy and stiff and preferably includes hydrocolloid or hydrogel materials. Slits may be provided in the carrier frame to permit one of more portions of the frame to be removed from the backing without removing the entire frame from the backing.

This is a continuation of application Ser. No. 09/450,242, filed Nov.29, 1999, now U.S. Pat. No. 6,264,976 entitled ABSORBENT DRESSING FRAMEDELIVERY SYSTEM (pending), which is incorporated herein by reference.

The invention relates to wound dressings, and more particularly to athin film composite dressing with an absorbent pad and a frame deliverysystem for the dressing.

BACKGROUND OF THE INVENTION

Hydrocolloid adhesive compositions that are formed as wound dressingshave been known for many years. Typically, these compositions comprise ablend of a polymer matrix, such as a rubbery elastomer likepolyisobutylene, in combination with one or more water-soluble orwater-swellable hydrocolloids, such as a dry powdered mixture of pectin,gelatin and carboxymethylcellulose. The adhesive composition is usuallycoated on at least one surface of a water-insoluble film to form arelatively thick, heavy wound dressing.

Commercially available examples of hydrocolloid wound dressings include“DUODERM™” and “DUODERM™ EXTRA-THIN” wound dressing (a product ofConvatec; Squibb and Sons, Inc., Princeton, N.J.; believed to be aKRATON™-based composition); TEGASORB™ wound dressing (a product ofMinnesota Mining and Manufacturing Company, St. Paul, Minn.; apolyisobutylene-based composition); RESTORE™ wound dressing (a productof Hollister, Inc., Libertyville, Ill.; believed to be an ethylene vinylacetate (EVA)-based composition); and COMFEEL™ wound dressing (a productof Coloplast International, Espergaerde, Denmark; believed to be aKRATON™-based composition). See, also, U.S. Pat. Nos. 4,231,369;4,477,325; 4,551,490; 4,738,257 and 5,633,010.

The delivery system for most of the above examples provide a simplerelease liner to protect the tacky hydrocolloid surface. One exceptionto this class is the TEGASORB™ wound dressing. This product has a thin,adhesive coated polymeric backing extended beyond the edges of theabsorbent hydrocolloid pad to form a border that will adhere to the skinand provide barrier to outside contamination as well as keep wound fluidcontained providing for a longer wear time.

A successful delivery system has been used on Tegaderm™ transparentdressings (a product of Minnesota Mining and Manufacturing Company, St.Paul, Minn.). The Tegaderm™ dressing comprises a thin polyurethane withan adhesive on one surface and a carrier or frame that facilitatesapplication. The Tegaderm™ transparent dressing, however, does notinclude a hydrocolloid or absorbent pad. See, also, U.S. Pat. No.5,531,855.

PCT Patent Publication No. WO 98/00080 shows the combination of apackage and a medical adhesive composite, such as a dressing. See, also,U.S. Design Pat. Nos. 408,541; 409,754 and 410,087 and U.S. Pat. No.(USSN: 08/887,523, filed Jul. 2, 1997), which are incorporated herein byreference.

SUMMARY OF THE INVENTION

The invention provides an absorbent dressing and delivery system thatfacilitates handling the extremely thin, flexible film border of thedressing during delivery to prevent wrinkling and adhering the film ofthe dressing to itself, which otherwise would interfere with the smooth,aseptic application of the dressing to a patient's skin.

The island dressing composite of the invention provides a carrierdelivered dressing having a conformable backing with a pressuresensitive adhesive coated on a bottom and a absorbent pad positioned onthe adhesive, and which is supported by a removable carrier attached tothe top face of the backing. In particular, the present inventionovercomes the problems discussed above by securing the carrier to thetop face of the backing with an overlapping form.

Furthermore, in one embodiment, the method and apparatus of the presentinvention provide such a carrier delivered dressing in which the windowis optionally removed prior to use by the consumer, thereby minimizingthe steps necessary to apply the dressings and reducing the waste streamat the consumer level.

In particular, the present invention provides an adhesive compositedressing comprising: (a) a conformable backing having top and bottomfaces; (b) a pressure sensitive adhesive coated on at least a portion ofthe bottom face of the backing; (c) a absorbent or medicated padprimarily in the center portion; (d) a liner releasably adhered to thepressure sensitive adhesive opposite the backing; and (e) a carrierreleasably attached to and covering at least a portion of the top faceof the backing, the carrier being nonpermanently attached to the backingand a cut in the carrier substantially defining a window proximate acenter of the carrier and overlapping at least a portion of the pad, thecarrier further being formed of material substantially more rigid thanthe backing to provide rigidity to the adhesive composite. The compositedressing may also include an optional low adhesion coating on the topface of the backing, in between the carrier and the top face of thebacking.

These and various other advantages and features of novelty whichcharacterize the invention are pointed out with particularity in theclaims annexed hereto and forming a part hereof. However, for a betterunderstanding of the invention, its advantages, and objects obtained byits use, reference should be had to the accompanying drawings anddescriptive matter, in which there is illustrated and describedpreferred embodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be further described with reference to the drawingwherein corresponding reference characters indicate corresponding partsthroughout the several views of the drawing, and wherein:

FIG. 1 is a top plan view of a preferred embodiment of the absorbent paddressing and delivery system according to the invention;

FIG. 2 is a bottom plan view of the dressing and delivery system of FIG.1;

FIG. 3 is a side schematic view of the dressing of FIGS. 1 and 2 takensubstantially along line 3—3 of FIG. 1;

FIG. 4 is a top plan view of an alternate preferred embodiment of theabsorbent pad dressing and delivery system according to the invention;and

FIG. 5 is a perspective, exploded view of another alternate preferredembodiment of the absorbent pad dressing and delivery system accordingto the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIGS. 1-3 depict a preferred embodiment of the absorbent pad dressingand delivery system designated in its entirety by the reference numeral10. The delivery system of this invention is particularly useful inconnection with a dressing in which a relatively heavy or stiffabsorbent pad 12 is positioned on a conformable backing 14 that is lightand flexible relative to the pad 12. In this preferred embodiment, bothof the absorbent pad 12 and the backing 14 have a generally kidney-shapeor outline, and are particularly designed for use a sacral dressing,although the invention is not limited to this shape or to sacraldressings. The preferred backing 14 is a transparent or translucentelastic film.

Preferably, a pressure sensitive adhesive (PSA) 16 is provided on alongone major surface 18 of the backing 14, and a low adhesion coating (lowadhesion backsize or LAB) 20 is provided on the other major surface 22of the backing 14. A description of a preferred low adhesion coating foruse with the present invention can be found in U.S. Pat. Nos. 5,531,855(Example 1), which is compatible with a heat seal bond described below.The low adhesion coating 20 reduces dressing changes due to unwanteddressing removal when other tapes or devices are placed on the dressing10 and removed, and reduces the surface friction of the dressing 10 onlinen or other fabrics, thereby offering additional protection againstthe accidental removal of dressing 10

Major surface 18 is sometimes referred to as the “bottom face” or “firstmajor surface” of the backing 14, and major surface 22 is sometimesreferred to as the “top face” or “second major surface” of the backing14.

A release liner 24 is attached to the exposed surface ofpressure-sensitive adhesive 16 on the bottom face 18 of the backing 14.The release liner 24 covers the PSA until the consumer is ready to applythe dressing 10. The release liner 24 may be a single piece or multiplepiece release liner, and may be part of or laminated to the package (notshown) containing the dressing, or merely enclosed along with thedressing 10 within the package.

The absorbent pad 12 of this dressing 10 is sometimes referred to as an“island pad” because the backing 14 extends substantially beyond theabsorbent pad 12, typically beyond the entire periphery of the pad 12.For example, the length and width of the backing could be 16.1 cm×21.9cm, and the length and width of the absorbent pad could be 12.3 cm×13.9cm. The pressure sensitive adhesive 16 on the peripheral portion of thebacking 14 not covered by the island pad 12 may be adhered to the skinof a patient. This portion of the backing 14 is thus not supported orreinforced by the relatively heavy and stiff absorbent pad 12, andabsent the benefits of the invention would be difficult to handlewithout folding, wrinkling or otherwise adhering to itself rather thanadhering to the skin.

FIG. 2 is a bottom view of dressing 10 with the liner 24 removed toexpose the adhesive layer 16 and absorbent pad 12, which is disposedproximate the center of the dressing 10. Although absorbent pad 12 isshown as centered on dressing 10 and as having a kidney-shape similarto, but smaller than, the backing 14, it can take any appropriate shapeand/or can be located off-center on the dressing 10 as desired.

A carrier frame 26 is attached to the top face 22 of the backing 14 overthe low adhesion coating 20. The carrier frame 26 extends alongsubstantially the entire periphery of the backing 14 and forms a window28 exposing a portion of the backing 14 overlying the absorbent pad 12with the backing 14 sandwiched between the frame 26 and absorbent pad12.

As used herein, a first piece can be said to “overlap” or “overlie” asecond piece if it covers a portion of either the second piece, or aportion of some third piece that is covered along its opposite side bythe second piece. In other words, one piece can “overlap” or “overlie”another piece even though separated by a third piece. More specifically,the carrier frame 26 can “overlap” or “overlie” the absorbent pad 12with the backing 14 positioned between the overlapped portions of theabsorbent pad 12 and carrier 24.

As used herein, the term “sandwiched” means that one layer isintermediate or between two other layers. For example, the backing 14may be considered an intermediate layer between the carrier frame 26 andthe absorbent pad 12, and thus is “sandwiched” between the frame 26 andabsorbent pad 12.

The preferred arrangement is such that:

(a) One or the other major surface of the backing 14 is covered byeither the absorbent pad 12 or the carrier frame 26 (or both)substantially throughout the extent of the backing 14;

(b). Substantially the entire periphery of the absorbent pad 12 isoverlapped by the carrier frame 26 so that the portion of the backing 14covered on one major surface by the absorbent pad is covered on theother major surface by the carrier frame 26, thus forming what might beconsidered a three-layer or double-supported “ring” (the shape of thering is defined by the periphery of the pad 12 and the window 28 of thecarrier frame 26, and in the first preferred embodiment will begenerally kidney-shaped); and

(c) Each of the carrier frame 26 and absorbent pad 12 are substantiallymore rigid than the backing 14.

The carrier frame 26 is preferably attached to the second major surface22 of the backing 14 (over low adhesion coating 20) with a heat sealbond. The heat seal bond between the carrier frame 26 and the backing 14is stronger than the bond between the pressure sensitive adhesive 16 andthe release liner 24 so that the backing 14 remains attached to thecarrier frame 26 when release liner 26 is removed from the dressing 10.Once the release liner 24 and dressing 10 are separated, only thecarrier frame 26 and absorbent pad 12 support (i.e. provide rigidity to)the backing 14.

Most preferably, the carrier frame 26 has several nonlinear cuts orslits 30, 32, 34 and 36, which may be controlled depth die cut so as notto cut the backing 14. Any of the slits 30, 32, 34 or 36 provides abeginning point at which the carrier frame 26 may be lifted from backing14 and peeled away. Several nonlinear slits 30, 32, 34 and 36strategically positioned around the frame 26 allow for distinct sectionsof the carrier frame 26 to be removed without removing the othersections to aid in the delivery over body contours. It is alsocontemplated that a section of the frame could be removed to betterconform to a catheter while the non-removed sections of the framefacilitate application of a dressing over the catheter.

Although each slit 30, 32, 34 and 36 may be a linear, they arepreferably nonlinear. Nonlinear slits 30, 32, 34 and 36 are believed toprovide more support for the backing 14 and carrier 24 because nonlinearslits are less likely to allow the carrier 24 to fold at the slit or cutline as compared to linear cuts. If frame 26 folds along one or more ofthe slits 30, 32, 34 or 36, the adhesive on the backing 214 will adhereto itself rendering the dressing 210 useless. Most preferably, the slits30, 32, 34 and 36 are provided by generally sinusoidal cuts 30, 32, 34and 36 as shown in FIGS. 1 and 2, although other nonlinear slits thattend to resist folding may also provide good service, such as zigzag,undulating, single or multiple tooth patterns or irregular ornonsymmetrical nonlinear slits.

Preferably, the frame 26 includes one or more tabs 38 and 40 extendingbeyond the perimeter of backing 14 to provide a means of removing thebacking/frame/adhesive composite from the release liner 24 and applyingthe composite without contacting the adhesive 16. For example, two tabs38 and 40 extend longitudinally outwardly from opposite ends of theframe 26 to provide a structure that can be gripped by fingers to peelthe dressing from the release liner 24. Most preferably, the releaseliner 24 includes two tabs 39 and 41 corresponding to the tabs 38 and 40of the frame 26 so that one tab (e.g., 39) of the liner 24 and one tab(e.g., 38) of the frame 26 may be grasped to separate the dressing andframe from the release liner 24.

FIGS. 1-3 depict a preferred kidney-shaped dressing 10, which isparticularly designed to be a sacral dressing. The periphery 42 ofpreferred embodiment of the dressing 10 has a concave edge portion 44,two minor convex edge portions 46 and 48 surrounding the concave edgeportion 44 and a major convex edge portion 50 defining the edge of thedressing opposite the concave edge portion 44. The minor convex edgeportions 46 and 48 and concave edge portion 44 thus form one side edgeof the frame 26 extending between the tabs 38 and 40, and the major edgeportion 50 forms the opposite side edge of the frame extending betweenthe tabs 38 and 40.

The opposite ends of the concave edge portion 44 may be considered asbeing defined approximately at the apex or pinnacle of each of the minorconvex edge portions 46 and 48. Such pinnacles are the point ofinflection where the edge of the dressing starts to curve inwardly toform the concave edge portion 44. The nadir of the concave edge portion44 is the point of inflection of the concave edge portion 44. The nadirof the concave edge portion 44 and the apex of the major convex edgeportion 50 define a line of symmetry that bisects the frame 26 (anddressing 10) into two substantially mirror image parts.

Most preferably, two of the slits 30 and 32 are arranged generallyadjacent the opposite ends of the concave edge portion 38 to facilitateremoval of the portions 46 and 48 of the frame adjacent the concave edgeportion 38, one slit 34 extending inwardly of the frame 26 fromgenerally adjacent the nadir of the concave edge portion 38, and oneslit 36 extending inwardly of the frame 26 from generally adjacent theapex of the major convex edge portion. The arrangement is such that theslit 34 adjacent the nadir of the concave edge portion 38 and the slit36 adjacent the apex of the major convex edge portion 50 extendsubstantially in directions along a common line (in the sense thatnonlinear slits can be considered to define a direction).

Slits 34 and 36 in FIG. 1 are depicted as each having the curve formedby a tab on one piece of the frame 26 and a concave edge on the adjacentpiece receiving the tab. Most preferably, in this example, the tabsforming slits 34 and 36 extend toward opposite ends of the frame 26.

The window 28 may be cut (e.g., controlled depth die cut) from a carrierblank to form a carrier frame 24 having a window exposing a portion ofthe top surface of the backing 14. The cut or window portion of thecarrier blank may be either removed during manufacturing or by theconsumer. Removal during manufacturing eliminates one step in thedelivery process for previously known window style dressings and reducesthe waste stream at the consumer level. Some customers, however, preferthat the portion of the carrier covering window 28 remains intact untilthe dressing 10 reaches the consumer.

Preferably, the absorbent pad 12 comprises a hydrocolloid and hydrogelpad 12 having a thickness of at least 1 mm (e.g., most preferably 3-9mm), and the backing 14 comprises a transparent elastic polymeric film(e.g., urethane) having a thickness no greater than 0.1 mm (e.g., mostpreferably 0.021-0.051 mm). It will be appreciated that in thispreferred embodiment the pad 12 is much thicker, stiffer and heavierthan the film backing 14.

Features of the embodiment in FIG. 4 that are similar to the features ofFIGS. 1-3 are designated by the same last of the reference numbers butwith the addition “100”.

FIG. 4 depicts an alternative preferred embodiment of the inventionsimilar in some respects to the embodiment of FIGS. 1-3 except that (a)the carrier frame 126 overlaps only a portion of the absorbent pad 112,and (b) a bridge 127 is provided on the frame 126 extending along thelength of the dressing to provide additional support of the frame 126 bythe absorbent pad 112. A slit 137 may be provided across the bridge 127to facilitate removing one side of the bridge and the adjacent frameportion before the other side of the bridge and its adjacent frameportion. The slit 137 may be linear or non-linear but is depicted aslinear because it is believed that absorbent pad 112 provides sufficientsupport for this slit 137 to be linear. The slit 137 is shown asextending generally along a common line with the apex and nadir of themajor convex edge portion 150 and concave edge portion 144, but could beoffset in either direction from this common line. In this embodiment thewindow 128 a and 128 b comprises two window portions 128 a and 128 bseparated by the bridge 127.

Features of the embodiment of FIG. 5 that are similar to the features ofFIGS. 1-3 are designated by the same last two digits of the referencenumbers but with the addition of “200”.

FIG. 5 depicts a second alternative preferred embodiment of theinvention similar in some respects to the embodiments of FIGS. 1-4except that

(a) The absorbent pad 212 is only overlapped by the frame 226 along theopposite ends 213 a and 213 b of the absorbent pad, and across anintermediate portion of the absorbent pad 212 by a bridge 227, thusproviding portions of the windows 228 a and 228 b that do not overly theabsorbent pad 212;

(b) The backing 214 has a generally rectangular shape with the cornerscut off;

(c) The windows 228 a and 228 b are each generally rectangular shapedwith longitudinal axes that a substantially parallel with one anotherand substantially perpendicular to the longitudinal axis of the frame226;

(d) The absorbent pad 212 has a generally rectangular shape having alongitudinal axis substantially parallel with the longitudinal axis ofthe backing 214 but substantially perpendicular to the longitudinal axesof the windows 228 a and 228 b;

(e) Four slits 230, 232, 234 and 236 are provided along the long sideedges of the carrier frame 226, and are arranged in two sets of twoslits (230 and 232, 234 and 236) with each set of slits extendinggenerally in the longitudinal direction of the windows (perpendicular tothe longitudinal direction of the frame 226);

(f) The bridge 227 does not include an intermediate slit; and

(g) The carrier pieces 229 a and 229 b covering the windows 228 a and228 b are depicted as staying in place until removed by the consumer.

An alternative embodiment of the invention is also contemplated in whichthe carrier frame has an opening such that the frame extends slightlyless than completely around the perimeter of the backing. The openingwould allow the dressing to be placed over catheters or other deviceswhile still attached to the frame to increase the ease of handling ofbacking.

The described embodiments are illustrative examples, and the features ofone embodiment may be used in connection with the other embodiments. Forexample, a bridge could be added to the embodiment of FIGS. 1-3.

Preferred Backing Materials

Suitable backings 14, 114 or 214 include, for example, nonwoven fibrouswebs, woven fibrous webs, knits, films and other familiar backingmaterials. The preferred backing materials are translucent ortransparent polymeric elastic films. Most preferably, the backing is ahigh moisture vapor permeable film backings. U.S. Pat. No. 3,645,835,the disclosures of which are hereby incorporated by reference, describemethods of making such films and methods for testing their permeability.

Preferably, the film/adhesive composite should transmit moisture vaporat a rate equal to or greater than human skin. Preferably, the adhesivecoated film transmits moisture vapor at a rate of at least 300 g/m²/24hrs/37° C./100-10% RH, more preferably at least 700 g/m²/24 hrs/37°C./100-10% RH, and most preferably at least 2000 g/m²/24 hrs/37°C./100-10% RH using the inverted cup method.

The backing is preferably conformable to anatomical surfaces. As such,when the backing is applied to an anatomical surface, it conforms to thesurface even when the surface is moved. The preferred backing is alsoconformable to animal anatomical joints. When the joint is flexed andthen returned to its unflexed position, the backing stretches toaccommodate the flexion of the joint, but is resilient enough tocontinue to conform to the joint when the joint is returned to itsunflexed condition.

A description of this characteristic of backings preferred for use withthe present invention can be found in issued U.S. Pat. Nos. 5,088,483and 5,160,315, the disclosures of which are hereby incorporated byreference. Particularly preferred backings are elastomeric polyurethane,co-polyester, or polyether block amide films. These films combine thedesirable properties of resiliency, high moisture vapor permeability,and transparency found in preferred backings.

Preferred Pressure Sensitive Adhesive

While any pressure sensitive adhesive 16, 116 or 216 can be used, thepreferred pressure sensitive adhesive is reasonably skin compatible and“hypoallergenic”, such as the acrylate copolymers described in U.S. Pat.No. RE 24,906, the disclosure of which is hereby incorporated byreference. Particularly preferred is a 97:3 iso-octylacrylate:acrylamide copolymer. Also preferred is an 70:15:15 isooctylacrylate: ethyleneoxide acrylate:acrylic acid terpolymer, as describedin U.S. Pat. No. 4,737,410 (Example 31), the disclosure of which ishereby incorporated by reference. Other useful adhesives are describedin U.S. Pat. Nos. 3,389,827, 4,112,213, 4,310,509, and 4,323,557, thedisclosures of which are hereby incorporated by reference. Inclusion ofmedicaments or antimicrobial agents in the adhesive is alsocontemplated, as described in U.S. Pat. Nos. 4,310,509 and 4,323,557both of which are hereby incorporated by reference.

The preferred pressure sensitive adhesives described above preferablytransmit moisture vapor at a rate greater to or equal to that of humanskin. While such a characteristic can be achieved through the selectionof an appropriate adhesive or through use of a nonwoven (e.g., meltblown) adhesive (as described in U.S. patent application Ser. No.08/980,541, filed Dec. 1, 1997, U.S. patent application Ser. No.09/201,954, filed Dec. 2, 1998, and PCT Publication No. WO 99/27975 (allof which are incorporated herein by reference)), it is also contemplatedin the present invention that other methods of achieving a high relativerate of moisture vapor transmission may be used, such as pattern coatingthe adhesive on the backing.

The preferred film and adhesive combinations is disclosed in U.S. Pat.No. 5,849,325 (Example 1), the disclosure of which is herebyincorporated by reference.

Preferred Absorbent Pad Materials

Absorbent pad 12, 112 or 212 can be manufactured of any of a variety ofmaterials including, but not limited to, woven or nonwoven cotton orrayon. Absorbent pad 12 is useful for containing a number of substances,including antimicrobial agents, drugs for transdermal drug delivery,chemical indicators to monitor hormones or other substances in apatient, etc.

The preferred island pad providing an absorbent matrix includes thenormal adhesives which are applied to the skin, or the hydrocolloidcompositions described in U.S. Pat. Nos. 5,622,711 and 5,633,010, thedisclosure of which is hereby incorporated by reference. Thehydrocolloid absorbent may comprise, for example, a naturalhydrocolloid, such as pectin, gelatin, or carboxymethylcellulose (CMC)(Aqualon Corp., Wilmington, Del.), a semi-synthetic hydrocolloid, suchas cross-linked carboxymethylcellulose (X-link CMC) (e.g. Ac-Di-Sol; FMCCorp., Philadelphia, Pa.), a synthetic hydrocolloid, such ascross-linked polyacrylic acid (PAA) (e.g., CARBOPOL™ No. 974P; B.F.Goodrich, Brecksville, Ohio), or a combination thereof. Preferably, thehydrocolloid absorbent component comprises from about 5 percent to about60 percent by weight of the adhesive composition. When preparing anadhesive composition for use in a wound dressing the hydrocolloidabsorbent preferably comprises from about 20 percent to about 40 percentby weight of the composition.

Preferred Release Liner Materials

Preferred release Liners 24, 124 or 224 can be made of kraft papers,polyethylene, polypropylene, polyester or composites of any of thesematerials. The liners are preferably coated with release agents such asfluorochemicals or silicones. For example, U.S. Pat. No. 4,472,480, thedisclosure of which is hereby incorporated by reference, describes lowsurface energy perfluorochemical liners. The preferred liners arepapers, polyolefin films, or polyester films coated with siliconerelease materials. Examples of commercially available silicone coatedrelease papers are POLYSLIK™ silicone release papers available fromRexam Release (Bedford Park, Ill.) and silicone release papers suppliedby DCP-Lohya Co. (Dixon, Ill.). The most preferred liner is 1-60BKG-157paper liner available from DCP-Lohya, which is a super calendared Kraftpaper with a water-based silicone release surface.

Other combinations of adhesives and liners are contemplated for use withembodiments according to the present invention. Those skilled in the artwill be familiar with the processes of testing a new adhesive againstdifferent liners or a new liner against different adhesives to arrive atthe combination of qualities desired in a final product. Theconsiderations pertinent to the selection of a silicone release linercan be found in Chapter 18 of the Handbook of Pressure SensitiveAdhesive Technology, Van Nostrand-Reinhold, 1982, pp. 384-403. U.S. Pat.No. 72,480 also describes considerations pertinent to the selection of aperfluoropolyether release liner.

Liners are available from a variety of manufacturers in a wide varietyof proprietary formulations. Those skilled in the art will normally testthose liners in simulated use conditions against an adhesive of choiceto arrive at a product with the desired release characteristics.

Preferred Carrier Materials

The preferred carrier material used to supply the carrier/carrier frame28, 128 or 228 is preferably substantially more rigid than the backing14, 114, 214 to prevent the backing 14, 114, 214 from wrinkling duringapplication. The carrier material can be heat-sealable to the backing14, 114, 214, with or without the low adhesion coating described above.In general, the preferred carrier materials include, but are not limitedto, polyethylene/vinyl acetate copolymer-coated papers and polyesterfilms. One example of a preferred carrier material is apolyethylene/vinyl acetate copolymer-coated super calendared Kraft paper(1-80BKG-157 PE; DCP-Lohya).

USE

In use, the liner 24, 124 or 224 is first removed from the dressing 10,110 or 210 leaving the frame 26, 126, 226/backing 14, 114,214/pressure-sensitive adhesive 16, 116, 216/absorbent pad 12, 112, 212composite intact. The user can then manipulate the dressing 10, 110, 210using tabs 38, 40 on the frame 26 while viewing the area to which thedressing 10, 110, 210 will be attached through window 28, 128 a/128 b or228 a/228 b, as the preferred backing 14, 114, 1214 is transparent ortranslucent.

To apply the wound dressing 10 to the sacral groove of a patient, (a)the portion(s) of the frame 26 adjacent the concave edge portion 44 ofthe dressing 10 (i.e. the portion(s) between slits 30 and 32) is removedfrom the backing 14 while leaving other portions of the frame 26 inplace on the backing 14; (b) the dressing 10 is then bent to form aconcave curve along the first major surface of the backing 14 with theadhesive-coated major surface 20 (bottom face) of the backing 14adjacent the concave edge portion 44 being along the top of the concavecurve; and (c) the concave edge portion 44 of the dressing 10 isinserted into the sacral groove first and the dressing 10 is adhered tothe patient over a sacral wound. The rest of the frame 26 is thenremoved.

EXAMPLE 1 Pressure Sensitive Adhesive/Film Backing

The adhesive composition of this example features a pressure sensitiveadhesive matrix blended with polymeric microspheres, and was prepared asfollows (from example 1 of U.S. Pat. No. 5,849,325.

To prepare the microspheres, a monomer mixture was prepared bydissolving 4.8 g of acrylic acid, 2.4 g of Carbowax™ 750 acrylate(polyethylene oxide acrylate) and 1.13 g Lucidol™-70 (70% benzoylperoxide) in 232.8 g of iso-octyl acrylate. A surfactant solution wasprepared by dissolving 0.75 g of sodium dodecyl benzene sulfonate in 360g of water. The monomer mixture was then added to the surfactantsolution, and the resulting mixture emulsified using a Gifford-Wood™mixer until the droplet size was less than 5 micrometers. The emulsionwas charged to a 1 liter baffled reactor, heated to 65° C., degassedwith N₂, and allowed to react for 8 hours. Microspheres having anaverage diameter of about 2 micrometers were formed during the reactionperiod.

The adhesive matrix was prepared according to the procedures describedgenerally in PCT Patent Publication No. WO 84/03837 using a monomermixture containing 70 parts by weight isooctyl acrylate, 15 parts byweight acrylic acid, and 15 parts by weight Carbowax™ 750 acrylate(polyethylene oxide acrylate). The matrix was then blended with themicrospheres (30 microspheres per hundred parts matrix) using aLightening-brand mixer and applied to a release liner made ofsilicone-coated kraft paper.

Next, a 25 micrometer thick film of Estane™ 58237 thermoplasticpolyurethane (B.F. Goodrich Co.) was extruded and laminated to theadhesive composition. The thickness of the adhesive composition was 25microns (1 mil). A dressing was prepared according to the proceduredescribed in Example 1 of Heinecke et al., U.S. Pat. No. 5,531,855,hereby incorporated by reference.

As various changes could be made in the above constructions,compositions and methods without departing from the scope of theinvention as defined in the claims, it is intended that all mattercontained in the above description or shown in the accompanying drawingsbe interpreted as illustrative and not in a limiting sense.

What is claimed is:
 1. A carrier delivered dressing comprising: an island dressing comprising a backing that comprises a first major surface and a second major surface, an adhesive located on the first major surface of the backing, and an absorbent island pad proximate the first major surface of the backing; and a carrier attached to the island dressing, the carrier being removably mounted on the second major surface of the backing, the carrier comprising a carrier frame defining a window within the carrier frame, wherein the absorbent island pad overlaps at least a portion of the carrier frame outside of the window.
 2. The carrier delivered dressing according to claim 1, wherein the carrier frame comprises at least one slit.
 3. The carrier delivered dressing according to claim 2, wherein the carrier frame comprises at least two slits.
 4. The carrier delivered dressing according to claim 3, wherein the island dressing comprises a sacral dressing having a periphery comprising a concave edge portion, the concave edge portion having opposite ends, wherein the two slits are located adjacent the opposite ends of the concave edge portion.
 5. The carrier delivered dressing according to claim 4, wherein the absorbent island pad comprises a hydrocolloid absorbent sheet material.
 6. The carrier delivered dressing according to claim 1, wherein the carrier further comprises a bridge portion extending across the window, wherein the bridge portion overlaps the absorbent island pad. 